Colored photographic image



. example, where Patented Mar. 12, 1940 Karl S chinzel,

man Kodak Company,

Rochester, N. Y., assignor to East- Rochester, N. Y., a corporation of New Jersey No Drawing. Serial No.

This invention relates 5 Claims.

to color photography and particularly to'a method for forming colored images. in photographic layers.

This application is a continuation in part of my prior application, Serial No. 139,759, filed April 29, 1937. Modern processes 0 volve the formation of images in a photographic of colored images in this pllshed by sensitizing to three regions of coating three differentially color photography inthree-color separation.

The formation way is usually accoma single photographic layer the visible spectrum or by sensitized layers on the same side or on opposite sides of a photographic support. In processes of this type it is frequently diflicult to form the third color image without affecting the two previously formed images or to form a colored image in the middle layer of three layers coated on the same side ot a single support.

It is, therefore, the principal object of the present invention to provide a colored image in method for forming a photographic layer by a chemical method which does not affect previously formed images.

A further object is to provide a method for forming a colored photographic image by direct objects will appear tion of my invention.

chemical conversion. Other from the following descrip- These objects are accomplished according to my invention by the direct conversion of a silver halide or silver ferrocyanide salt such as silver into a colored photographic image.

In processes of color photography;

described in my prior application,

such as those Serial No.

139,759, three difierentially sensitized layers may be coated graphic support. After on the same side of a single photoexposure of a film ofthis nature it is necessary to form three differently colored images in the separate layers. For the layers are sensitive, respectively, to the red, green, and blue regions of the spectrum, the final images are colored, respectively, blue-green, magenta and yellow. Dye images may be formed in various ways in these layers as by toning, colorcoupling, etc. The image in the layer nearest'the support is usually colored first and the image in the middle layer or top layer colored second. The final image must be colored by some means which does not destroy or adversely affect the images in the other layers.

This is frequently a difficult procedure particularly in a reversal process where there is a sensitive silver salt in the primary development.

the layers after Application December 30, 1938, 248,517. In Austria May 9, 1936 I have found that after the formation of a coloredimage in one of the layers of a multilayer film, ior example, in

the layer nearest the support, and in one of the remaining layers,

that an image in-the by a direct conversion of the third layer may be formed remaining silver salt into colored substances or into mordantsor basic dyes or into last method is not preferred sin precipitants or acid dyes. This ce acid dyes usually stain the gelatin and cannot be washed out of the highlight portions as easily as basic dyes. The sensitive silver salt, for example, silver chloride or silver bromide may be treated directly or may as converted into ferrocyanide and treated as silver ierrocyanide. first to remove any metallic It is more desirable silver remaining after the formation of the first two part-color images, to reduce the silver halide of the remainingemulsion to metallic silver and to convert it into silver ferrocyanide or a mixture'of silver.

ferrocyanide with lead potassium ferricyanide.

This procedure can tion of an image in or in the top emulsion ferrocyanide by means of be followed for the formathe middle emulsion layer layer. The silver salt-in the top emulsion layer might be converted to a color compound according to the present process before the formation of an image in the middle,

or both the middle or the colored compound iormed halide is one which resists the d cording to the preferred my invention, however, the silv verted to the colored compound present process only after col lower emulsion layers if from the silver evelopment. Ac-

method of carrying out er halide is conaccording to the ored images are formed in the other two emulsion layers.

The method for forming the colored image from silver halideaccording .to my invention involves the chemical conversion of the silver salt into a colored compound upon treatment with certain compounds containing group. The compound formed silver salt which is much less original silver halide, and the c the mercaptan in this way is a soluble than the onversion is performed chemically, not depending on exposure of the silver salt to form a latent image.

Com

pounds, such as thio-glycolic acid anilide and thio-glycolic-B-naphthalide, for example, form yellow precipitates with silver salts and may be used to form yellow images in photographic layers according to my invention.

The ferrocyanides of silver and other metals are also suited for conversion into colored compounds with mercaptans to form yellow or red salts. All of these reactions can, of course, be accom plished with the HC==CH (where x is CHaCHaOH or other heterocyclic ring system) 7 o aldehyde can be condensed to aniis with the amino groupo! the initial substances mentioned above and then reduced. Aromatic disulfides o1 sulfochlorides can also be used for forming a chain of the initial substance or at amino dyes and then It is to be understood that colored photographic images according to my invention can be formed in any of the layers of a multi-layer or in a single layer sensitive to only the spectral region or containing differentially sensitized silver halide grains. Mercaptans other 1. The method of forming a colored photographic image in a silver halide layer containing convert the silver halide into a salt.

3. The

salt

4.'The method of forming a colored photographic KARL SCHINZEL. 

